1. Field of the Invention
The present invention relates to a substrate processing system, a substrate surface processing apparatus, a substrate surface inspecting apparatus, a substrate surface inspecting method, and a storage medium storing a program for implementing the method, and more particularly relates to a substrate processing system and a substrate processing method according to which a substrate surface having foreign matter attached thereto can be inspected.
2. Description of the Related Art
A substrate processing system that carries out plasma processing on wafers as substrates has a processing module that houses a wafer and carries out the plasma processing, a load lock module that transfers each wafer into the processing module, and a loader module that takes out each wafer from a container housing a plurality of the wafers and transfers the wafer into and out of the load lock module. In such a substrate processing system, foreign matter such as particles or grease may become attached to a surface of a wafer when the wafer is transferred. Such foreign matter attached to the surface of a wafer causes defects in semiconductor devices manufactured from the wafer, for example short-circuiting of wiring, and hence must be removed.
The width and so on of wiring grooves in semiconductor devices is becoming smaller year by year. To cope with this, the target value for the size of foreign matter to be detected is stipulated by the ITRS (International Technology Roadmap for Semiconductors) as shown by the roadmap shown in Table 1 below.
TABLE 1Year of Production200420052006200720082009Critical foreign454035332925matter size (nm)
According to the above roadmap, foreign matter of size 29 mm must be detectable by 2008.
Substrate surface inspecting apparatuses that use a scattered laser light method have been known from hitherto as apparatuses for detecting the size of particles attached to the surface of a wafer. Such a substrate surface inspecting apparatus has an inspection stage on which the wafer is mounted and rotated, a laser beam irradiating unit that irradiates a laser beam onto the surface of the rotating wafer, a light receiver that receives some of scattered light scattered from the surface irradiated by the laser beam, and a photoelectric converter that converts an optical signal from the light receiver into an electrical signal. In the case that a particle is attached to the surface of the wafer, upon the particle being irradiated by the laser beam, the magnitude of the scattered light changes in accordance with the size of the particle. Such a substrate surface inspecting apparatus detects the size and number of particles attached to the surface of the wafer based on the voltage of the electrical signal produced through the conversion by the photoelectric converter and the number of such signals (see, for example, Japanese Laid-open Patent Publication (Kokai) No. H01-219546).
However, the size of particles that can be detected by such a substrate surface inspecting apparatus using the scattered laser light method is determined by the resolution of the photoelectric converter. The resolution of current photoelectric converters is 50 to 70 nm at best, and hence such a substrate surface inspecting apparatus cannot detect particles of the 2004 critical foreign matter size stipulated in the above roadmap.
As a substrate surface inspecting apparatus capable of detecting particles of size approximately 30 nm, there is known a substrate surface inspecting apparatus that scans the surface of a wafer using an EB (electron beam), and examines the surface with an SEM (scanning electron microscope); however, such a substrate surface inspecting apparatus can only inspect a few wafers per day, and hence is not suitable for mass production of wafers.
That is, at present there is no substrate surface inspecting apparatus that is capable of detecting particles of size approximately 30 nm and is suitable for mass production of wafers.